Telegraph system.



H. P. CLAUSEN.

TELEGRAPH SYSTEM. 1,232,224;

APPLICATION FILED OCT-1.1915- PatentedJuly 3, 1917 UNITED srA'rEs PATENT ornron.

HENRY P. CLAUSEN, OF MOUNT VERNON, NEW YORK, ASSIGNDR, BY MESNE ASSIGN- MEETS, TO WESTERN ELECTRIC COMPANY, IN-LGDBPORZAwTED; A COREORATION OF' new YORK.

TELEGRAPH- SYSTEM Patented July 3, 1917.

Application filed October 1, 1915. Serial No. 53,586.

To all whom it may concern:

Be it known that I, HENRY I. CLAUSEN, a citizen of the United States, residing at Mount Vernon, in the county of WVestchester and State of New York, have invented certain new and useful Improvements in Telegraph Systems, of which the following is a full, clear, concise, and eXact description.

This invention relates to improvements in telegraph systems, and has for its principal object to provide means for automatically rendering a signal effective at an open transmitting key in case an associated key-closing switch remains open unnecessarily.

In accordance with this invention, a thermal relay and a signal are included with the regular telegraphic equipment at each station on a telegraph line. Upon the line circuit being interrupted by' a key-closing switch remaining open unnecessarily for an interval of time exceeding that of a predetermined period, the thermal relay will operate 1tio include the signal in shunt on the open In the drawing, a circuit arrangement of a telegraph line circuit is shown in which 1, 2 and 3 represent three separate telegraph stations connected serially with a main line conductor 4, line batteries 5 and 6, and the earth connections. Identical equipment is present at each of the stations where similar characters of reference indicate similar apparatus, and except for the thermal relays, signals and keys, designated 10, 11 and 12, respectively, the devices and circuit arrange ment are of well known type; therefore, the present description will only relate to the operations necessary in practising the features of this invention.

When the circuits are in the normal position as shown in the drawing, a thermal coil 18 of the thermal relay 10 is continuously energized over a series circuit which includes the battery 17, telegraph sounder 23 and contacts 16 of a line relay 15. An expansible member 19 associated with the thermal coil 18 is accordingly expanded to move a member 20 out of engagement with a spring 21,

thereby retaining contacts 22 open.

In describing the operations which take place in the automatic reclosing of an open key, let it be assumed that a keyclosing switch 13 at station 1 remains in the open position and that the associated transmitting key 25 continues idle. The result ing cessation of current in the line circuit 4:, due to the open key 25, permits the line relay 15 to become de'elnergized and open its contacts 16, thereby interrupting a series circuit formed through the battery 17, sounder 23 and the thermal coil 18 of the thermal relay 10. Deenergization of the thermal coil 18 permits the member 19 to contract and cause the member 20 to depress the spring 21 to close the contacts 22. Closure of the contacts 22 includes a signal bell 11 in bridge on the open key 25, thereby reclosing the line circuit and rendering the signal, preferably a single-stroke bell, responsive to a call for this'station or to messages transmitted between other stations on the line circuit.

At stations where the regular sounder would be considered a sufficient signal, a conductor may be substituted for the signal and the bell dispensed with.

The characteristics of the thermal relay are such that the lapse of a predetermined interval of time is necessary before the expansible member 19 will move from either of the alternate positions to operate the associated contacts. This feature provides against premature inclusion of the signal 11 around a key from which a message is being transmitted, and also permits the signal to be retained for a predetermined period in bridge on an open key.

Operation of the key 12 permits immediate use of the transmitting key 25 following its having been bridged by the signal bell 11 and before the lapse of a suli'icient interval of time to permit the reoperation of the thermal relay 10 which would take place, as described, on the reclosing of the line circuit.

What is claimed is:

1. In a telegraph system, a sending means and a receiving means, a line circuit included therewith, a signal, means for opening said line circuit in order to render said receiving means effective, and a thermally actuated relay for reclosing said line circuit through said signal upon the expiration of a predetermined interval of time.

2. In a telegraph system, a sending means maining idle While in the effective position and a receiving means, a line circuit in,- for an interval of time exceeding that of a eluded therewith, a signal, means for renderpredetermined period. 1 10 ing said sending means either efl ective or In Witness whereof, I hereunto'subscribe 5 ineffective, and a thermally actuated relay my name this 28th day of September, A. D.

for including said signal in bridge of said 1915. I 1 sending means upon the sending means re- HENRY P. CLAUSEN.

five cents each, by addressing the Commissioner of Patents,

Copies of this patent may be obtained for Washington, D. 0.? 

